1. Field of the Invention
The present invention relates to a vision measuring machine, such as a microscopic measuring device or a non-contact view measuring CMM, and in particular to measurement using a program (a part program).
2. Description of the Related Art
Conventionally, manually operating vision measuring machines and CNC (Computerized Numerical Control) vision measuring machines are used for inspection of ICs, read frames, IC packages, and so on. Generally, in measurement using a vision measuring machine, an object to be measured (workpiece), such as an IC, is placed on a stage, and photographed by an imaging means, such as a camera, so that an image thereof is displayed on a CRT. Subsequently, a part program for workpiece measurement is activated. A part program is a program prepared by storing information on a series of measurement procedures for one sample, taught by an operator, as well as information on the position and shape of the workpiece. When a part program is activated, commands are sequentially read from a prepared part program file. In response to a stage moving command, a driving means moves the stage. In response to a tool command, images of tools, such as a box tool, a circular tool, and so on, are added to a workpiece image displayed on the CRT. In this procedure, an edge point is detected using the provided tool, and a continuous edge is approximated from detected points using a least square method or the like. In response to an operation execution command, a designated operation, such as a line width operation, a circle center operation, a circle radius operation, and so on, is executed with respect to the workpiece image, based on the continuous edge.
As described above, in a conventional vision measuring machine, for automatic measurement, a measurement program including a measurement route is prepared for every workpiece to be measured, and executed. For measurement of a plurality of workpieces of an identical shape, such a measurement program is first prepared by manually measuring one workpiece and recording the measurement procedure, known from the manual measurement, and thereafter, while placing the remaining workpieces on the stage one by one, coordinate matching measurement (measurement reference position adjustment) is applied to the workpiece then on the stage, followed by execution of the measurement program prepared.
Note that coordinate matching measurement, which can be made manually, is usually made by executing a workpiece coordinate system measuring program (a Part Coordinate System, or PCS, program) while placing the workpiece one at a time on a position on the stage marked with tape or the like.
This, however, is troublesome and time consuming as each workpiece must be placed on a stage for measurement, and measuring programs must be exchanged for every type of workpieces when workpieces of a plurality of different types are to be measured.
In order to address the above problem, a plurality of workpieces may be collectively placed on the stage, and measured using a single measurement program. However, a single measurement program as currently in use is an integration of a plurality of measurement programs, each dedicated to a specific type of workpiece, such a program is thus inevitably lengthy and difficult to be composed. In addition, should any error be caused while measuring a plurality of workpieces, the measurement program must be amended, which may take time. Once the amended measurement program is resumed, workpieces measured before the-error in the measuring program must be measured again. Such repeated measurement is wasteful. Further, as the results of measurements of a plurality of workpieces obtained by repeatedly executing a single part program are stored in a single file (a result file), the result file must be edited every subsequent application of statistical processing to the measurement data. This may complicate statistical processing.
Also, as measurement of a plurality of workpieces on a stage may generally take time, unmanned, automatic measurement at night or during a holiday is highly desired. That is, it is highly desirable that measurement of workpieces on a stage be continued until completed, even when an error occurs during the measurement. Also desired is prompt post-measurement detection as to which workpieces on the stage are within tolerance, and which do not. It may often be desired that workpieces failing tolerance can be easily remeasured. As these demands can not be met by conventional measuring devices, demand for a device or method for readily and efficiently measuring numerous workpieces remains unsatiated.
The present invention has been conceived to overcome the above problems and aims to provide a device, method, and medium for efficiently measuring numerous workpieces through simple operation.
In order to achieve the above objects, according to the present invention, there is provided a vision measuring machine, comprising a stage for bearing measurement objects placed thereon, an imaging device for capturing an image of the measurement objects placed on the stage, and a processing device for measuring measurement object images in an image captured by the imaging device, wherein the processing device divides the stage into a plurality of sections to form a plurality of measurement sections each having a measurement object image, sets a measurement program to each of the plurality of measurement sections, and measures each of the measurement object images in the plurality of measurement sections based on a corresponding measurement program.
Also, according to the present invention, there is provided vision measuring machine, comprising an imaging device for capturing images of a plurality of measurement objects on a pallet segmented into a plurality of sections, and a processing device for measuring measurement object images in an image captured by the imaging device, wherein the processing device divides a measurement area into a plurality of sections to form a plurality of measurement sections, sets a measurement program to each of the plurality of measurement sections, and measures each of the measurement object images in the plurality of measurement sections based on a corresponding measurement program.
Here, preferably, the processing device determines whether or not measurement data on each of the plurality of measurement sections is within a predetermined tolerance, and outputs a GO/NG judgement for each of the plurality of measurement sections.
Also, preferably, the processing device outputs measurement data on each of the plurality of measurement sections.
Further, preferably, the processing device measures all other measurement sections in the plurality of sections even though measurement disorder should be caused to any measurement section.
Still further, preferably, the processing device measures only the measurement section selected in the plurality of sections.
Still further, the plurality of sections each have a desired shape, and are arranged in matrix. Preferably, each measurement section is a closed cell.
Also preferably, the processing device captures images of a plurality of measurement sections at the same time, and executes, simultaneously or sequentially, each measurement program set to each measurement section.
In addition, preferably, the processing device may preset a measuring program for each shape to be executed for every shape element. The processing device recognizes a shape element of a measurement object image in a measurement section, and selectively executes a suitable measurement program according to the results of recognition processing.
Further, preferably, the measurement program may be a program in which a numeric part thereof may be replaced by a variable as necessary.
The processing device may correct a measurement error.
The vision measuring machine of the present invention may further comprise positioning means for positioning a palette relative to the machine.
The vision measuring machine may also comprise an automatic workpiece exchanger for automatically exchanging measurement objects.
The vision measuring machine may further comprises an automatic palette exchanger for automatically exchanging palettes.
Yet further, according to the present invention, there is provided a vision measuring method for processing an image obtained by photographing a plurality of measurement objects placed on a stage, to thereby measure the measurement objects. This method comprises the steps of correlating each of a plurality of measurement sections in a plurality of sections to each of the plurality of measurement object images; setting a measurement program to each of the plurality of measurement sections; and measuring in each of the plurality of measurement sections according to a corresponding measurement program.
Yet further, according to the present invention, there is provided a vision measuring method for processing a captured image of a plurality of measurement objects in a palette segmented into a plurality of sectors, to thereby measure the measurement objects. This method comprises the steps of dividing a measurement area bearing a plurality of measurement objects into a plurality of sections to form a plurality of measurement sections each correlating to one of a plurality of measurement object images, setting a measurement program to each of the plurality of measurement sections; and measuring in each of the plurality of measurement sections according to a corresponding measurement program.
Here, the above method further comprises the step of displaying data indicating whether or not a result of measurement of each of the plurality of measurement sections is within a predetermined tolerance.
Also, the above method may further comprise the step of displaying a result of measurement of each of the plurality of measurement sections.
Further, in the above method, at the step of measurement, even though measurement disorder should be caused to one measurement section, all other measurement sections may be measured.
Still further, the above method may further comprise a step of selecting a measurement section in a plurality of sections so as to measure only the selected measurement section at the measurement step.
Also, the plurality of sections each preferably have a desired shape, and are arranged in matrix. Preferably, the measurement section is a closed cell.
At the measurement step, preferably, images of the plurality of measurement sections are captured simultaneously, and measurement programs each set to each measurement section may be executed simultaneously or sequentially.
The setting step includes a step of setting a measurement program to be executed for every shape element.
The measurement section further comprises a step of recognizing a shape element of a measurement object image in a measurement section, and a step of selectively executing the measurement program based on a result of the recognition.
Preferably, the measurement program is a program in which a numeric part thereof may be replaced by a variable as necessary.
Further preferably, the step of measurement may comprise an error correction step for correcting a measurement error.
Still further, preferably, the step of measurement may comprise a step of exchanging measurement objects, and a step of exchanging palettes.
As described above, in the present invention, a plurality of workpieces are handled collectively in units of a plurality of sections. This is different from the conventional art, in which a plurality of workpieces are individually measured. Each of the plurality of workpieces corresponds to each measurement section in the plurality of sections, and selection of a measurement section enables designation of a corresponding workpiece. Moreover, measuring programs can be easily set to a plurality of workpieces for measurement by setting a measuring program to each measurement section in a plurality of sections.
The technical concept that a measurement program is set to each measurement section in a plurality of sections can be applied to a variety of situations. For example, cases wherein a plurality of sections are arranged in matrix or wherein workpieces of an identical type are present in a row can be handled by setting identical measuring programs collectively to a row. A case wherein only some of a plurality of workpieces are to be selectively measured can be handled by selectively setting measurement programs to corresponding measurement sections in the plurality of sections.
In addition, even should measurement error or disruption be caused to one of a plurality of workpieces being successively measured, according to the present invention, measurement can continue with other measurement sections to finish measurement for all other measurement sections in the plurality of sections. This differs from the conventional art, in which measurement is discontinued when disrupted because a single measurement program is used for all workpieces on a stage. The present makes this, possible because a measuring program is set individually to each measurement section, such as a cell.
xe2x80x9cA measurement programxe2x80x9d contains a PCS part program, as well as a measurement part program, and so on. A PCS part program is a program for matching, prior to measurement, the coordinate system of a vision measuring machine to a reference position of each workpiece. A measurement part program is a program for detecting an edge of a workpiece image by using a measuring tool, and for executing a predetermined operation (a line width operation, a circle center operation, and so on), based on the detected edge.
Basically, the position or size of each of a plurality of sections is desirably determined. It is therefore possible to designate one or more island-shaped sections indicative of a part or parts for measurement in a workpiece and a remaining workpiece part, though respective sections arranged orderly in matrix could facilitate positional designation of a plurality of sections.
For measurement, one of a plurality of sections may be imaged and the associated program may be executed. Alternatively, images of some sections in a plurality of sections may be captured and the associated programs may be simultaneously or sequentially executed. This latter method can reduce measurement time, and is particularly effective in reducing a measurement time when each measurement section is small and arranged side-by-side.
Further, a measurement program may be determined in advance for each shape element (a circle, a rectangular, a straight line, and so on). In actual workpiece measurement, a shape element of each measurement object image is recognized based on the imaging of each section, and a measurement program to be applied is selected based on the result of recognition. This can improve efficiency in measurement program preparation. In this case, an example effective measurement program would be a parametric program disclosed in JP Laid-open No. Hei 8-14876, in which a numeric part thereof is replaced by a variable upon necessity. In actual measurement, a shape parameter (a diameter, center coordinates of a circle, and so on) value, obtained based on the result of recognition of the measurement object image is substituted into the variable before executing the measurement program.
With this arrangement, in an example of circle measurement, a measurement program free from dependency on the size or position of a circle can be prepared. This enables sharing of a measurement program, and therefore significant reduction of a program preparation time.
In addition, when various error corrections, such as corrections on expansion/contraction with a workpiece or measurement device due to temperature, on measuring displacement accuracy, on volumetric measuring accuracy, and so on, can be applied to improve measuring accuracy. The present invention can be applied to a case where a palette segmented into a plurality of sections is placed on a stage, as well as a case where one workpiece having a plurality of parts for measurement or a plurality of workpieces are regularly arranged on the stage. A palette is positioned by a positioning means provided on the stage, whereby the position of the palette relative to the device can be readily defined, and measurement can be facilitated.
The present invention may also comprise an automatic workpiece exchanger for automatically exchanging workpieces. This enables unmanned successive operations, even at night, and thereby further reduces costs. In addition, an automatic palette exchanger may also be provided, which can produce identical advantage to that by an automatic workpiece exchanger.
Further, according to the present invention, there is provided a computer readable medium storing an image processing program. The program causes a computer to correlate each of a plurality of measurement sections in a plurality of sections to each of a plurality of measurement objects, set a measurement condition to each of the plurality of measurement sections, and measure for each of the plurality of measurement sections according to the measurement condition.